Grout seal for tail shield of tunneling machine



Feb. 1o, 1.910 4 C. RWILMS 3,494,136

GRUT SEAL FOR TAIL SHIELD OF TUNNELING MACHINE INVENTOR. Gl W/ MS BYM/M Feb. 10, 1970 c; A. WILMs y 3,494,136 GROUT SEAL FOR TAIL SHIELD 0F TUNELING MACHINE Filed June 28, 1968 4 Sheets-Sheet 2 '/0' 2/4 25 Z/l Z/ 64a 4. (ZX/2%? BY ,676-, 6: M M- Feb. 1o, 1970 C. A, WMS 3,494,136

GROUT SEAL FOR TAIL SHIELD OF TUNNELING MACHINE Filed June 28, 1968 4 Sheets-Sheet 3 INVENTOR. C4Q 4. W/ MS HdM/mu- Feb. 1o, 1910 c. A. wlLMs l 3,494,136

GROUT SEAL FOR TAIL SHIELD OF TUNNELING MACHINE l Filed June 2a, 1968 4 sheets-sheet 4.

G76- Il.

INVENTOR. Zl 4. W/MS 'SYM /w United States Patent O U.S. Cl. 61-85 7 Claims ABSTRACT OF THE DISCLOSURE A tunneling machine having a cutting head, a cylindrical shell, a tail shield at the rearward extremity of the shell, a tunnel liner disposed within the tunnel immediately to the rear of the tail shield and having its forward portion extending partially within the tail shield, and a grout seal secured to the rearward extremity of the tail shield and slidingly engaging the tunnel liner. Specific details of construction of the grout seal and method of making it are also disclosed.

BACKGROUND OF THE INVENTION It has heretofore been known to pour concrete or grout around the exterior cylindrical surface of a tunnel liner that is disposed within a tunnel just rearwardly of a tunneling machine, and at the same time to employ some kind of means for sealing the interior of the tunneling machine from the exterior of the liner so as to prevent the grout or concrete from flowing into the tunneling machine. The sealing methods utilized prior to the present invention have not, however, been reliable or satisfactory in operation.

The present invention has provided a novel grout seal for the tail shield of a tunneling machine, including a unique method of attachment of the grout seal to the tail shield and for engaging the tunnel liner. The present invention also provides a novel method of manufacture of such a grout seal.

The object of the present invention, therefore, is to provide a new and greatly superior apparatus and method for sealing the flow of grout or concrete from the space exterior to a tunnel liner so that it will not flow into the interior of an associated tunneling machine.

DRAWING SUMMARY FIGURE 1 is a cross-sectional elevational view of a tunneling machine located in operative position within a tunnel, and which incorporates the novel grout seal of the present invention.

FIGURE 2 is a transverse cross-sectional view taken on the line 2-2 of FIGURE 1.

FIGURE 3 is an enlarged detailed view taken within the circle 3 3 of FIGURE l.

FIGURE 4 is a fragmentary cross-sectional view taken on the line 4--4 of FIGURE 3.

FIGURE 5 is a cross-sectional View taken on the line 5--5 of FIGURE 4.

FIGURE 6 is a view like FIGURE 4, showing the deformation of the grout sealing ring after the grout has been poured.

FIGURE 7 is a view similar to FIGURE 4, but showing the two opposite sides of the grout seal when the tail shield is in its position of maximum eccentricity relative to the tunnel liner.

FIGURE 8 is a perspective view of an extrusion of resilient material from which the grout seal ring is made.

FIGURE 9 is a radial cross-sectional view of a forming die within which the grout sealing ring is being formed.

3,494,136 Patented Feb. 10, 1970 "ice FIGURE 10 is a perspective view of a quarter section of the grout sealing ring.

FIGURE ll is a perspective view showing two quarter sections of the sealing ring about to be joined together.

FIGURE l2 is a perspective view of the complete grout seal ring just prior to being assembled onto an inner metal ring which is used in supporting it from the tail shield.

PREFERRED EMBODIMENT As shown in FIGURE 1 a tunneling machine generally identified as 15 is disposed within a body of earth 10 and has formed therein a generally cylindrical tunnel wall 11. At its forward end the tunneling machine 15 carries a cutting head 16 which bears against the tunnel face 12. In its central portion the tunneling machine 15 has a cylindrical outer shell 17 which is extended rearwardly to form a cylindrical tail shield 18 at the rearward extremity of the tunneling machine.

The tunneling machine 15 shown in FIGURE 1 has been traveling toward the tunnel face 12, being guided to maintain precise line and grade requirements by a surveying and/or guidance system, the details of which are not shown. Some distance to the rear of the tunneling machine 15 and its tail shield 18 there is a cylindrical tunnel liner 30 disposed within the tunnel, and it will be noted that the outer diameter of the liner 30 is sufficiently less than the outer diameter of tail shield 18 so that the liner 30 could in fact have occupied a position inside the tail shield 18. The liner 30 is surrounded by an annular space which separates it from the tunnel wall 11, and that annular space is filled with concrete or grout 32 which, as of the time shown in FIGURE l, has not only been poured in place but has already hardened. The longitudinal axis A of liner 30 therefore correctly reflects the desired line and grade of the tunnel, and as of the time shown in FIGURE 1 the guidance of the tunneling machine 15 is directed toward continuing to dig the tunnel in a position concentric to that axis A.

Another tunnel liner section 31 is disposed just forwardly of the tunnel liner 30, being identical in its construction to the liner 30. Liner 30 has a radially inwardly extending flange at its forward end, and liner 31 has a radially inwardly extending flange at its rearward end, these two flanges being secured together about the circumference of both liners by means of a plurality of bolts 60. Thus the liner section 31 is supported from the liner section 30 and the in-place grout or concrete 32, so as to also be concentric to the axis A. As of the point of time shown in FIGURE 1 the annular space surrounding liner 31 and disposed between liner 31 and tunnel wall 11 has not yet been filled with grout, although at the bottom of FIGURE 1 there is shown a portion of grout 34 that is beginning to be placed in that annular space. The forward extremity of liner 31 extends within the rearward portion of tail shield 18, as shown in dotted lines. The rearward extremity of tail shield 18 carries a grout seal 20 whose function and purpose is to prevent the newly poured grout 34 from owing into the interior of the tail shield 18 or tunneling machine 15.,

In the particular illustration of FIGURE 1 the longitudinal axis of the tunneling machine 15 is vertically aligned with the longitudinal axis A of liners 30 and 31, hence the tail shield 1'8 is perfectly concentric to the forward end of liner 31. It will be recognized, however, that the steering action of the tunneling machine 15 cannot always tbe perfect, hence the successful operation of the tunneling machine must necessarily contemplate an eccentric condition as is subsequently described in conjunction with FIGURE 7 of the drawings.

As shown in FIGURE 2 the cylindrical liner 31 consists of four quarter-section members 35 which are bolted together. In each member 35 the cylindrical wall is identified as 35a; the radially inwardly extending forward flange as 35b; the radially inwardly extending flange by means of which is is joined to the immediately adjacent member 35 is identified as 35C; and a removable grout plug which closes a grout opening 35e is identified as 35d, And as also shown in FIGURE 2 the new or wet grout or concrete 34 is being forced into the annular space between liner 31 and tunnel wall 11 by means of a pressure hose 61 which extends through the grout opening 35e of the lowermost member 35.

Reference is now made to FIGURES 3 to 5, inclusive, which show in enlarged detail the construction of the tail shield and grout seal. FIGURES 3 to 5, inclusive, refiect the machine position of FIGURE 1 in which the tail shield is concentric to the liner 31, and in which the liner is therefore concentric to the tail shield, as is indicated by a corresponding legend in FIGURE 4. The tail shield 18 (FIGURE 4) is a rather thick metallic cylinder whose rear extremity terminates in a flat circumferential shoulder. An outer cylindrical metal ring 21 has an exterior diameter which is preferably identical to the exterior diameter of tail shield 18, and the outer ring 21 has its forward end secured by the circumferential weld 21a to the rear extremity of the tail shield to form an extension thereof. However, the radial thickness of the outer metal ring 21 is significantly less than that of tail shield 18, and is in fact only about one-third the thickness of tail shield 18.

An inner metal ring 22 has an inner diameter which is preferably identical to the inner diameter of the tail shield 18, and its thickness is likewise about one-third the radial thickness of tail shield 18. The forward end of inner ring 22 butts against the circumferential shoulder 18a of tail shield 18, but is not welded thereto, for reasons which will be subsequently explained. It will be noted that the length of inner ring 22 is significantly less than the length of outer ring 21, so that the rearward extremity 2lb of the outer ring 21 projects significantly to the rear of the rearward extremity 22a of inner ring 22.

The grout seal ring 50 shown in FIGURES 3 to 5, inclusive, is a resilient ring having a cylindrical :base portion 51 that is disposed between the outer metal ring 21 and the inner metal ring 22. The outer metal ring 21, inner metal ring 22, and sealing ring base portion 51, together form a sandwich construction having a composite thickness which is preferably identical to the radial thickness of tail shield 18, as clearly seen in FIGURE 4.

Grout seal 50 also includes a fiange 52 integrally formed with the ibase 51, and which extends from the rearward circumferential extremity of the base 51 in a generally radially inwardly direction therefrom. The rearward extremity of flange 52 maintains a sealing engagement with the outer cylindrical surface of liner section 31, as best seen in FIGURE 4.

Reference is now made to FIGURE l2 which illustrates the manner in which the grout seal is assembled to the tail shield. The grout seal ring 50 (consisting of four quarter-section members 48 which have been joined together) is placed adjacent the inner metal ring 22. At this time the inner metal ring 22 has a plurality of openings 22b formed therein about its entire circumference, the openings 22h being enlarged on the interior surface of the member 22 so as to receive the bolt heads of bolts 23, as will be subsequently described. At the time shown n FIGURE 12 the inner diameter of base 51 of the grout seal 50 is significantly less, about 2% less, than the outer diameter of the metal ring 22. It is therefore necessary to stretch the base 51 in order to place it about the outer surface of ring 22. Some kind of tool, not shown, is then used for insertion through the openings 22b so as to form corresponding holes in the base portion S1 of the grout seal ring 50. The assembly of these two members is then inserted inside the outer metal ring 21, and bolts 23 are inserted from the interior of the inner metal ring 22. It will be noted that the openings 2211 in the inner ring 22 are not threaded, but the corresponding openings of outer metal ring 21 are threaded, and the length of bolts 23 is so selected that the bolts do not project beyond the exterior cylindrical surface of the outer ring 21.

Thus the assembly illustrated in FIGURE 4 is achieved by welding the outer metal ring 21 to the tail shield 18 to form an extension thereof; stretching the base portion 51 of grout seal 50 around the inner metal ring 22; thereafter inserting the combination of inner ring 22 and grout seal 50 within the outer metal ring 21, and subsequently inserting a plurality of the bolts 23 for radially supporting the inner ring 22 and seal ring base 51 from the outer ring 21.

Reference is now made to FIGURES 8 to 1l, inclusive, which illustrate the method or process of manufacturing the grout seal ring 50. As sho-wn in FIGURE 8 a long at extrusion 40 is formed of resilient material, having a relatively thin portion 41 on one side and a relatively thick portion 42 on the other side, portion 42 being of about twice the width of the portion 41. FIG- URE 9 illustrates a forming and curing die which includes a male or inner member 45 and a female or outer member l46, each of these members extending circumferentially through an angle of so as to form a quarter-section member 48, as shown in FIGURE l0. The extrusion 40 is cut to the proper length to form one quarter-section member 48 and is placed between the die members 45 and 46; a combination of heat and pressure is applied to the die members; and after the proper curing time the ends of the resilient member are trimmed and a quarter-section member 48 has then been formed. As shown in FIGURE 9 the extrusion portion 41 forms the base portion 51 of the grout seal ring; the extrusion portion 42 forms the grout seal flange 52; a small notch or recess 52C is formed on the inner surface of the juncture of base S1 and flange 52; the inner fiat surface of flange 52 is identified as 52a while the outer fiat surface is identified as 52b. After four of the segments 48 have been for-med, these may be joined together in the manner illustrated in FIGURE 11, by a conventional vulcanizing process in which the ends of the members 48 are slit open at 48a and fabric pieces 49 are inserted into the slits and then the joint is cured for an appropriate period of time. Thus the complete grout seal ring 50 shown in FIGURE 12 is formed.

The mechanical action of the grout seal ring 50 during its use will now be described. As shown in FIGURE 4 the rearward extremity of iiange 52 forms a sliding seal with the cylindrical outer surface of liner 31, maintaining this seal as the tunneling machine 15 moves forward relative to the liner 31. However, a stretching action is required before the liner 31 can be inserted inside the fiange 52, and FIGURE 4 shows by means of dotted lines 55 the essentially radially inward position which the fiange 52 initially occupies before it is stretched to permit the insertion of the liner within it. When the greater portion of the length of liner 31 is exposed to the rear of tail shield 18, as shown in FIGURE 1, it is then time to pour the grout 34. FIGURE 6 shows the action of the grout seal flange 52, and it will be seen that the ange 52 bends a great deal so that its outer surface 52b is concave while its inner surface 52a is convex. The result of this action is, however, a frictional engagement at the line 63 between a considerable length of the flange 52 and the liner 31. Thus a very effective sealing action is obtained.

FIGURE 7 illustrates the operation of the grout seal when the tunneling machine is eccentric relative to the liner. on one side of the liner (the upper portion of FIG- URE 7) the outer surface of the liner is in flush engagement with the inner surface of the inner metal ring 22 as well as the full inner surface 52a of flange 52 of the grout seal. Thus a veij effective seal is obtained with or without the presence of the grout. On the other side of the liner (the lower part of FIGURE 7) the flange 52 inclines at about a 45 angle relative to tail shield 18 and liner 31, before the grout is poured. When the grout is poured the flange 52 deforms into the position shown by dotted lines 56, and a sealing engagement is achieved at the line 64 through a length of both the flange 52 and the liner 31 that is still suicient to provide a very effective seal.

The invention has been described in considerable detail in order to comply with the patent laws by providing a full public disclosure of at least one of its forms. However, such detailed description is not intended in any way to limit the broad features or principles of the invention, or the scope of the patent monopoly to be granted.

Having described the invention, what is claimed as new in support of Letters Patent is:

1. A grout seal for the tail shield of a tunneling machine comprising, in combination:

an outer metal ring having an exterior diameter which is substantially equal to the exterior diameter of the tail shield, and having one of its ends secured to the extremity of said tail shield to form an extension thereof, said outer metal ring being of a radial thickness which is significantly less than the radial thickness of said tail shield;

an inner metal ring whose radial thickness is also significantly less than the thickness of the tail shield, and having an inner diameter which is essentially equal to the inner diameter of said tail shield;

a resilient sealing ring having a cylindrical base which is disposed in a state of tension between said outer metal ring and said inner metal ring, said outer and inner metal rings and said base together having a composite thickness which is substantially equal to the radial thickness of the tail shield;

said sealing ring having a flange integrally formed with said base thereof which extends radially inwardly from the end of said base at the rearward end of said inner metal ring; and

fastening means which secure said inner metal ring to said outer metal ring and pass through corresponding openings in said sealing ring base.

2. A grout seal as claimed in claim 1 wherein the length of said inner metal ring is significantly less than the length of said outer metal ring.

3. A grout seal as claimed in claim 1 wherein said sealing ring flange at the point where it joins said sealing ring base is substantially thicker than said base, said ange projecting inwardly from said base and forming essentially an extension of said inner metal ring; whereby the tendency of said lange to flex inwardly under load is minimized.

4. A grout seal for the tail shield of a tunneling machine comprising, in combination:

a resilient sealing ring having a cylindrical base whose normal diameter is less than the interior diameter of said tail shield, and having a ange integrally formed with said base which extends radially inwardly in essentially a truncated conical configuration;

an inner metal ring and an outer metal ring which are concentrically disposed and so arranged as to provide a rearward extension of said tail shield, at least one of said rings being secured to said tail shield;

said sealing ring base being stretched around said inner metal ring in the assembled condition of said grout seal;

said sealing ring flange at the portion thereof adjoining said sealing ring -base being thickened so as to project inwardly from said base adjacent to and in Contact with the rearward extremity of said inner metal ring;

thereby to minimize the tendency of said ange to detlect inwardly under load.

5. A grout seal as claimed in claim 4 wherein said outer metal ring is of greater length than said inner metal ring and projects rearwardly about said thickened portion of said sealing ring flange.

6. A grout seal as claimed in claim 4 wherein said inner metal ring, said sealing ring base, and said outer metal ring together have a radial thickness which is substantially identical to the radial thickness of said tail shield.

7. A grout seal as claimed in claim 4 wherein said outer metal ring is welded to the extremity of said tail shield, a plurality of threaded openings are formed in said outer metal ring for receiving bolts, corresponding bolt holes are formed in said inner metal ring and in said sealing ring base; and which further includes a plurality of bolts having their heads disposed at the inner surface of said inner metal ring and extending through said inner metal ring and sealing ring base t0 threadedly engage said threaded openings in said outer metal ring.

References Cited UNITED STATES PATENTS 311,656 2/1885 Hall 61-84 549,586 11/1895 Rothwell 61-84 993,507 5/1911 Collins 277-212 X 1,484,188 2/1924 ORourke 61-84 1,989,110 1/1935 Penniman 277-152 X 2,348,587 5/1944 Antonelli 277-212 X 3,379,445 4/1968 Fisher 277-212 X 3,410,098 11/1968 Winberg 61-85 DENNIS L. TAYLOR, Primary Examiner U.S. C1. X.R. 61-43 

